Inhibition of apoptosis in human breast cancer as related to prognosis

Breast tumorigenesis proceeds through an accumulation of specific genetic alterations. Breast malignant transformation is dependent on not only the rate of cell production but also on apoptosis, a genetically programmed process of autonomous cell death. It may also be important in the overall growth dynamics of neoplastic cells, both in the natural history and when they are exposed to chemotherapy or radiation. This study evaluated the biological and clinical implications of spontaneous apoptosis in human breast cancer. Apoptosis was measured in 8 normal breast tissues and 91 human breast cancer samples by Apoptag end labeling method. We found there was a significant inhibition of spontaneous apoptosis in breast cancer cells compared with normal breast epithelium. In 91 breast cancer samples, apoptotic index (AI) was strongly associated with lymph node metastasis; Low apoptosis of tumor cells was more frequent in poorly differentiated tumors and has a poor outcome.

Reverse use dependence of Kv4.2 blockade by 4-aminopyridine

4-Aminopyridine (4AP) can block various K channels with different state dependences; block occurs in the activated state or in the closed state. The use of K channel clones to study the mechanism and structural determinants responsible for the state dependence of 4AP actions has been hampered by the fact that, for all the K channel clones examined so far, 4AP binding and unbinding occur mainly in the activated state. We report here that 4AP binding to a fast inactivating K channel encoded by Kv4.2 in Xenopus oocytes occurred exclusively in the closed state. The binding rate was slow and independent of membrane voltage in the range from -80 to -120 mV. The binding rate was linearly related to 4AP concentration, yielding apparent binding and unbinding rate constants of 0.012 mM-1 s-1 and 0.062 s-1, respectively. 4AP dissociation from Kv4.2 occurred in two processes, a slow process in the closed state (in a voltage range from -70 to -40 mV) and a fast process in the activated state, which suggested that the closure of the activation gate of Kv4.2 did not prevent the entry or exit of 4AP molecules but slowed these processes. 4AP slowed the rate of Kv4.2 decay during depolarization, consistent with the notion that channel inactivation occurred only after 4AP dissociation. Inactivating Kv4.2 channels prevented 4AP binding. Therefore, 4AP binding and Kv4.2 inactivation were mutually exclusive. This, in conjunction with the observation that 4AP blocked Kv4.2 channels from the intracellular side of the cell membrane, suggests that the 4AP binding site is on the cytoplasmic surface of the Kv4.2 channel at, or adjacent to, the domains involved in channel inactivation. The distinct features of 4AP actions on the time course of transient outward current in human ventricular myocytes suggest that Kv4.2-like subunits are important in the formation of these channels in human heart.

Activation of locus coeruleus enhances the responses of olfactory bulb mitral cells to weak olfactory nerve input

The main olfactory bulb (MOB) receives a dense projection from the pontine nucleus locus coeruleus (LC), the largest collection of norepinephrine (NE)-containing cells in the brain. LC is the sole source of NE innervation of MOB. Previous studies of the actions of exogenously applied NE on mitral cells, the principal output neurons of MOB, are contradictory. The effect of synaptically released NE on mitral cell activity is not known, nor is the influence of NE on responses of mitral cells to olfactory nerve inputs. The goal of the present study was to assess the influence of LC activation on spontaneous and olfactory nerve-evoked activity of mitral cells. In methoxyflurane-anesthetized rats, intracoerulear microinfusions of acetyicholine (ACh) (200 mM; 90-120 nl) evoked a four- to fivefold increase in LC neuronal discharge, and a transient EEG desynchronization and decrease in mitral cell discharge. LC activation increased excitatory responses of mitral cells evoked by weak (i.e., perithreshold) nasal epithelium shocks (1.0 Hz) in 17/18 cells (mean Increase = 67%). The discharge rate of mitral cells at the time that epithelium-evoked responses were increased did not differ significantly from pre-LC activation baseline values. Thus, changes in mitral baseline activity do not account for the increased response to epithelium stimulation. These findings suggest that increased activity in LC-NE projections to MOB may enhance detection of relatively weak odors.

Synchronization of two passively mode-locked erbium-doped fiber lasers by an acousto-optic modulator and grating scheme

We synchronize two passively mode-locked erbium-doped fiber lasers by adjusting only the cavity length to correct both the repetition rate and the phase. The interlaser jitter is less than 6 ps (1.3 times the pulse width) and is extracted from the cross correlation of the two lasers. The lock can be maintained for extended periods of time. These results are obtained by use of a novel acousto-optic-modulator-grating scheme, which provides an equivalent of 300 microm in cavity length tuning with a bandwidth of 10 kHz. These parameters are 30 times the length and 10 times the bandwidth of a typical piezoelectric transducer.

Localization of the human RGR opsin gene to chromosome 10q23

The human RGR gene encodes an opsin protein (retinal G protein-coupled receptor), which is expressed in Müller cells and the retinal pigment epithelium and is thought to play a role in the visual process. To investigate a possible linkage of the RGR gene to retinal dystrophies, the locus of the gene was mapped on human metaphase chromosomes. Genomic and cDNA fragments of the human RGR gene were used as probes for fluorescence in situ hybridization. Analysis of the fluorescence signals on high-resolution banded chromosomes showed that the RGR gene is localized to human chromosome 10q23. This result now provides for the rapid analysis of this gene with respect to inherited diseases of the retina.

trp, a novel mammalian gene family essential for agonist-activated capacitative Ca2+ entry

SUMMARY

Capacitative calcium entry (CCE) describes CA2+ influx into cells that replenishes CA2+ stores emptied through the action of IP3 and other agents. It is an essential component of cellular responses to many hormones and growth factors. The molecular basis of this form of Ca2+ entry is complex and may involve more than one type of channel. Studies on visual signal transduction in Drosophila led to the hypothesis that a protein encoded in trp may be a component of CCE channels. We reported the existence of six trp-related genes in the mouse genome. Expression in L cells of small portions of these genes in antisense orientation suppressed CCE. Expression in COS cells of two full-length cDNAs encoding human trp homologs, Htrp1 and Htrp3, increased CCE. This identifies mammalian gene products that participate in CCE. We propose that trp homologs are subunits of CCE channels, not unlike those of classical voltage-gated ion channels.

Cloning, sequencing and expression of the CAMP factor gene of Streptococcus uberis

The gene coding for the CAMP factor from a strain of Streptococcus uberis (ATCC 9927) was cloned in Escherichia coli. Chromosomal DNA from Streptococcus uberis was used to construct a gene library in plasmid pTZ18R and six CAMP-reaction positive clones were obtained from a total of 10,000 transformants. One clone, pJLD21, was subcloned and the CAMP factor gene was located in a 3.2 kb BamHI fragment. The nucleotide sequence of Streptococcus uberis CAMP factor gene was determined and the deduced amino acid sequence is highly homologous to the corresponding Streptococcus agalactiae protein. Immunoblot analysis revealed that the recombinant strain pJLD21 expressed a protein with a molecular weight of 28 000. Antibodies raised against purified Streptococcus uberis CAMP factor cross-reacted with Streptococcus agalactiae protein B.

Laser demonstration of diode-laser-pumped neodymium-doped strontium fluorovanadate

The laser properties of diode-laser-pumped neodymium-doped strontium fluorovanadate samples cut perpendicular to the x(a) and y axes have been investigated. A slope efficiency of 36% for the 1.065-µm laser line and a lasing threshold of 6.8 mW have been measured for the x(a)-axis-cut crystal. Data are also presented for the laser's performance as a function of crystal temperature and for the variation of the central peak wavelength with the incident pump power.

[CT scanning and treatment of intracranial tuberculoma]

OBJECTIVE

To evaluate the value of CT scanning and the efficacy of anti-tuberculosis short-course chemotherapy in intracranial tuberculoma patients.

METHOD

The CT manifestations and the clinical characteristics of 55 intracranial tuberculoma patients were analysed.

RESULTS

44 out of 55 patients were cured. Among them, 40 patients' lesions were entirely resolved, while other 11 cases, clinical symptoms were subsided and still under treatment. In the contrast enhancing CT scanning, plate shaped or ring-form shadows were shown surrounding the lesions of tuberculoma. The characteristical features were more special for diagnosis and the positive rate was higher than that of other laboratory findings. The incidence of intracranial tuberculoma was found to be higher in children and juvenile patients who lived in rural areas.

CONCLUSIONS

Enhancing CT scanning is valuable for diagnosis of intracranial tuberculoma. The anti-tuberculosis short-course chemotherapy used nowadays with which almost all the intracranial tuberculoma patients can be cured and only few of them need surgical operation.

Mice deficient for the amyloid precursor protein gene

To understand the in vivo function of the amyloid precursor protein (APP) we generated an APP null mutation in mice by homologous recombination in embryonic stem (ES) cells. We show here that homozygous APP deficient mice were produced at expected frequencies. Neither APP mRNA nor protein could be detected in these animals. Yet the homozygous APP mutant mice are fertile and do not show overt abnormalities at up to 12 weeks of age. Neuroanatomical studies of the brain did not reveal significant differences in the knockout mice as compared to the wild-type controls. These results argue against an essential function of APP in mouse embryonic and early neuronal development.

Inhibition of rabies virus infection by an oligodeoxynucleotide complementary to rabies virus genomic RNA

To develop antirabies virus-specific agents, eight oligodeoxynucleotides (ODN) complementary to either rabies virus genomic RNA (negative polarity) or rabies virus transcripts (mRNA) were synthesized and tested for their activity to inhibit rabies virus infection in cell cultures. It was found that the ODN RH+1 complementary to rabies virus genomic RNA blocked almost completely rabies virus infection at concentrations as low as 2 microM, whereas ODN complementary to viral transcripts did poorly even at concentrations as high as 20 microM. The antigenomic ODN also has the ability to inhibit cell-to-cell spread of rabies virus, which is an indicator for protection of rabies virus infection in vivo. These results indicate that ODN complementary to rabies virus genomic RNA have strong ability to inhibit rabies virus infection in cell culture and may have the potential to be used for therapy in clinical rabies.

Increased cation permeability in mutant mouse red blood cells with defective membrane skeletons

Cellular cation homeostasis in mouse erythrocytes with defective membrane skeletons was examined in three mouse mutants, hemolytic anemia (sphha/sphha), spherocytosis (sph/sph), and normoblastosis (nb/nb), and compared with reticulocytes produced by repetitive bleeding of congenic normal mice. To assess reticulocyte maturity, nucleic acid and transferrin receptor contents were measured by fluorescence flow cytometry; mutant cells were somewhat more mature than normal reticulocytes by these criteria. Red blood cell (RBC) sodium contents (Nac+) in homozygous sphha/sphha, sph/sph, and nb/nb animals were 30.1 +/- 0.9, 28.9 +/- 0.3, and 26.9 +/- 1.5 mmol/L cell, respectively, whereas cellular potassium (Kc+) was 102 +/- 2.6, 101 +/- 7.8, and 97.4 +/- 3.0. Nac+ and Kc+ in normal reticulocyte preparations were 11.3 +/- 0.7 and 123 +/- 10, respectively. Net Na+ and K+ fluxes in the presence of ouabain were markedly increased in mutant RBCs. Sodium uptake was 14.8 +/- 1.6, 15.4 +/- 3.3, and 14.7 +/- 3.1 mmol/L cell/h in sphha/sphha, sph/sph, and nb/nb mutants, respectively, whereas K+ loss was 17.0 +/- 4.0, 15.0 +/- 3.8, and 14.1 +/- 2.6. Normal mouse reticulocytes gained Na+ at a rate of 3.9 +/- 1.0 mmol/L cell/h and lost K+ at 6.0 +/- 2.1, rates indistinguishable from those in mature mouse RBCs. Potassium loss from sphha/sphha and nb/nb cells was not dependent on the presence of a Na+ gradient, and net cation movements were insensitive to bumetanide (sphha/sphha and nb/nb RBCs) and to chloride replacement with sulfamate (nb/nb cells). We conclude that mutant mouse RBCs with dysfunctional membrane skeletons have increased passive permeability to monovalent cations. These findings support a role of the membrane skeleton in the maintenance of the membrane permeability barrier and suggest that the abnormal permeability associated with human hereditary spherocytosis and elliptocytosis may be a consequence of the membrane skeleton defects reported in these disorders.

Deoxygenation-induced cation fluxes in sickle cells. IV. Modulation by external calcium

Net cation movements were measured in low-density sickle red blood cells (SS RBC) in the presence and absence of oxygen. External Ca2+ (Ca2+o) partially inhibited deoxygenation-induced fluxes of both Na+ and K+. Deoxygenation-induced Na+ influx was reduced by 2 mM Ca2+o to 0.71 +/- 0.04 (SE) of its value in Ca(2+)-free solutions, whereas this ratio was 0.90 +/- 0.05 for K+ efflux (P < 0.01 by paired t-test). Because Ca2+o inhibited Na+ influx more than K+ efflux, net cation loss in deoxygenated SS RBC was higher in the presence of Ca2+o. In separate experiments, Ca2+o reduced deoxygenation-induced Na+ influx to 0.66 +/- 0.03 of its Ca(2+)-free value compared with 0.77 +/- 0.03 for Rb+ influx (P < 0.001), indicating relative selectivity of this effect for Na+ over Rb+. However, this effect is not specific for Ca2+ because other divalent cations also inhibited deoxygenation-induced Na+ and K+ fluxes. Under the conditions of these experiments, no evidence for K+ channel activation was found, indicating that K+ loss measured in deoxygenated SS RBC was mediated by the deoxygenation-induced pathway. These studies show that in the presence of Ca2+o deoxygenation-induced Na+ influx and K+ efflux are unbalanced. This pathway can, therefore, mediate cation loss and contribute directly to cellular dehydration in SS RBC.

Conjugation fidelity and bistability in a high-efficiency mutually pumped phase conjugator with ring channels

We describe a high-efficiency mutually pumped phase conjugator with ring channels in a bird-wing incident geometry in copper-doped potassium sodium strontium barium niobate. A transmissivity as great as 35% is measured. Optical switching is obtained. The dependence of phase-conjugation fidelity on the geometric parameters and the input-beam ratio is discussed. Some suggestions are proposed to improve the fidelity further. The response times as a function of the input-beam ratio with the input beam kept constant are measured, and the least-squares minimum is used to simulate the fitting curve equations and to explain the formation of optical switching and the reduction or improvement of image fidelity.

Resistance to fever induction and impaired acute-phase response in interleukin-1 beta-deficient mice

We used gene targeting in embryonic stem cells to introduce an IL-1 beta null allele in mice. The IL-1 beta-deficient mice develop normally and are apparently healthy and fertile. The IL-1 beta null mice responded normally in models of contact and delayed-type hypersensitivity or following bacterial endotoxin LPS-induced inflammation. The IL-1 beta-deficient mice showed equivalent resistance to Listeria monocytogenes compared with wild-type controls. In contrast, when challenged with turpentine, which causes localized inflammation and tissue injury, the IL-1 beta mutant mice exhibited an impaired acute-phase inflammatory response and were completely resistant to fever development and anorexia. These results highlight a central role for IL-1 beta as a pyrogen and a mediator of the acute-phase response in a subset of inflammatory disease models, and support the notion that blocking the action of a single key cytokine can alter the course of specific immune and inflammatory responses.

beta-Amyloid precursor protein-deficient mice show reactive gliosis and decreased locomotor activity

In several pedigrees of early onset familial Alzheimer's disease (FAD), point mutations in the beta-amyloid precursor protein (APP) gene are genetically linked to the disease. This finding implicates APP in the pathogenesis of Alzheimer's disease in these individuals. To understand the in vivo function of APP and its processing, we have generated an APP-null mutation in mice. Homozygous APP-deficient mice were viable and fertile. However, the mutant animals weighed 15%-20% less than age-matched wild-type controls. Neurological evaluation showed that the APP-deficient mice exhibited a decreased locomotor activity and forelimb grip strength, indicating a compromised neuronal or muscular function. In addition, four out of six homozygous mice showed reactive gliosis at 14 weeks of age, suggesting an impaired neuronal function as a result of the APP-null mutation.

[Antikeratin antibodies: another specific antibodies in rheumatoid arthritis patients]

Sera from 107 patients with rheumatoid arthritis (RA), 120 patients with other rheumatic diseases and 60 blood donors were tested with indrect immunofluorescence on the middle third of Wistar rat oesophagus as a substrate for the presence of antikeratin antibodies (AKA). By labelling the stratum corneum and stratum spinosum with IgG antibodies, three patterns of reaction were distinguished. Among them, only one pattern which showed an intense linear laminated fluorescence on stratum corneum and a weak fluorensence on stratum spinosum was valuable for the diagnosis of RA, with a specificity of 99% and a sensitivity of 23%. It was also found that they were not related to the presence of rheumatoid factor or anti-RA 33,000/36,000 antibodies. Thus, AKA might be another marker antibody in RA.

Alternative splicing in human retinal mRNA transcripts of an opsin-related protein

An opsin-related gene encodes a putative RPE-retinal G-protein-coupled receptor (RGR) that is most homologous to the visual pigments and invertebrate retinochrome. A splice variant of human RGR mRNA can be demonstrated by the sequence of isolated cDNA clones and by the amplification and analysis of human retinal mRNA. The shortened transcript contains a deletion of 114 nucleotides that correspond exactly to the sequence of exon 6 in the human rgr gene. The predicted RGR variant lacks the putative sixth transmembrane domain and has a calculated molecular weight of 27,726. Variable amounts of a 28-kDa protein were found in the retinas of some individuals by immunoblot assay. Since a similar shortened RGR transcript was not detected in bovine retina or RPE, the RGR variant is not essential for vertebrate vision. Analysis of the structure of the rgr gene and of the sequences of cDNA clones indicates that the truncated mRNA may be produced through alternative splicing of pre-mRNA from which a cassette exon is removed and the predicted RGR variant is radically altered in primary structure.

beta-Galactosidase transgene expression in transplanted rabbit retinal pigment epithelial cells in vivo

BACKGROUND

Intraocular transplantation of genetically modified cells that release a particular substance could have a major impact on the treatment of various ocular diseases. We studied the expression of the reporter gene beta-galactosidase (lacZ) in transplanted retinal pigment epithelial (RPE) cells in vivo.

METHODS

RPE cells from pigmented rabbits were transduced with the beta-galactosidase gene in a retroviral vector. Cells were then assayed for gene expression and transplanted subretinally into the eyes of New Zealand White rabbits. RPE cells that were transduced with a similar vector without the beta-galactosidase gene were used as controls. Rabbits were killed on days 1, 7, and 21 and the eyes processed for transmission electron microscopy

RESULTS

Neomycin-resistant rabbit RPE cells that showed beta-galactosidase activity were generated within 2-5 weeks. After transplantation, viable RPE cells that expressed the transgene and that phagocytosed rod outer segments were observed on days 1, 7, and 21

CONCLUSIONS

The results show that generation of genetically modified RPE cells is feasible and that the transplanted cells remain viable and continue to express the transgene in the subretinal space of the host animal for at least 21 days. Transplantation of such genetically modified RPE cells could provide a new tool for studying retinal diseases and, potentially, for correcting metabolic abnormalities in retinal degenerations and dystrophies.

Asymmetric transmission device using Fe-doped KTa(x)Nb(1-x)O(3) crystal

A new type of asymmetric optical transmission device based on contradirectional two-wave mixing between an incident beam and its backward-scattering beams in Fe-doped KTa(x)Nb(1-x)O(3) crystal is demonstrated. The transmittance ratio of the beams propagating in opposite directions can be adjusted by a change in the angle between the incident beam and the c axis; the maximum ratio is nearly 50:1 at only one incident beam. Approximate solutions of two opposite transmittances are derived and discussed. It is possible to use this device as an optical isolator or an optical diode.

[Aorto-profunda femoris bypass grafting in the treatment of aorto-ilio-femoral atherosclerotic occlusive disease]

Fourteen patients with aorto-ilio-femoral or ilio-femoral atherosclerotic occlusive disease were treated with aorto-profunda femoris bypass grafting. Excellent results were confirmed after a mean follow-up period of 15 months. Ankle-brachial index raised from 0.1 +/- 0.12 before operation to 0.64 +/- 0.26 months after operation. The authors considered that the profunda femoral artery plays an important role in aorto-femoral arterial reconstruction. It is a good outflow providing arterial blood to severely ischemic legs with occlusion of aorto-ilio-superficial femoral or ilio-superficial femoral arteries.